The Florida Oyster Cultch Placement Project is a Natural Resource Damage Assessment (NRDA) Phase III Deepwater Horizon early restoration project. As a result of the Deepwater Horizon oil spill and associated response activities, oyster reefs located along Florida’s Panhandle suffered adverse impacts. This project seeks to foster oyster reef habitat development, which would help compensate the public for Spill-related injuries and losses to oyster habitat and benthic secondary productivity.
Healthy oyster reefs play a vital role in the environment — they provide habitat for marine life, improve water quality, and support local fishing communities. This project aims to bring those benefits back by rebuilding degraded oyster habitats in targeted areas along Florida’s Gulf Coast.
To restore these reefs, we placed more than 61,000 cubic yards of reef-building material, known as cultch, across nearly 300 acres of existing oyster bars in three bay systems:
This material gives oyster larvae (called spat) a place to settle and grow, helping to rebuild reefs naturally.
Oyster reefs are vital to the health, economy, and culture of the Florida Panhandle. By restoring these reefs, this project:
Florida has been involved in rehabilitating oyster reefs for more than sixty years and provides a multi-dimensional approach built on decades of experience. The restoration techniques used in this project are well-established and widely recognized as effective for rebuilding oyster reef habitat.
To see how the reefs have responded to our restoration efforts, we monitor oyster abundance, growth, and survival on a yearly basis. Our observations allow us to determine if the reefs have reached population levels capable of sustaining commercial harvest. These results help guide future restoration efforts and ensure long-term success.
To determine the relative condition of oyster resources, an estimate of harvestable oysters is determined using the Florida Department of Agriculture and Consumer Services' (FDACS) Standard Oyster Resource Management Protocol, which has been utilized in Apalachicola Bay since 1982. FDACS uses a scale that states that 400 bags/acre could be harvested from productive artificially constructed reefs within two years of planting cultch. The scale is as follows:
The collected monitoring data is analyzed by CPAP staff to determine the success of the restoration work and compiled into annual monitoring reports.
Along with the annual monitoring reports that are published by CPAP, an interactive PowerBI dashboard was created which enables users to explore our monitoring data through dynamic visuals, making the complex data more accessible and engaging— far beyond what static graphs or traditional reports can offer.
In Apalachicola Bay, 22,111 live oysters and 5,888 dead oysters have been sampled thus far. The number of live oysters has declined steadily from the first round of sampling to the most recent (Round 5), with the lowest count recorded in Round 5.
The majority of oysters collected across all rounds were spat-sized (0-25 mm), which made up 79.89% of all live oysters sampled. In Round 5, spat made up about half of the total, at 52.57%, with seed-sized oysters (26-74 mm) representing 30.64%, and adult harvestable oysters (75 mm and larger) making up the rest (16.80%). While the total number of live oysters in Round 5 of monitoring decreased from Round 4, there was a slight increase in the number of adult oysters observed.
When analyzing the bay based on geographical parameters:
Still, overall productivity has dropped. Based on the FDAC's Standard Oyster Resource Management Protocol, none of the sites in Apalachicola Bay are currently productive enough to support commercial harvest. Only Lighthouse Bar came close, with an estimate of about 146 harvestable oyster bags per acre — still below the 200 bags/acre necessary to support commercial harvest.
The spatial extent of our restored oyster reefs was also determined using side-scan sonar to collect imagery data of our cultched reefs. This allowed us to determine that about 65% of the reef footprint still contains hard substrate necessary for spat settlement, representing just over 83 acres of the original 128-acre restoration area.
In St. Andrews Bay, to date, 57,966 live oysters and 7,424 dead oysters have been sampled, with numbers having increased significantly since the start of the project. The latest round (Round 5) saw the highest numbers yet, at 17,823 live and 1,021 dead oysters observed, with live counts showing an increase across all oyster size classes.
Key highlights:
Estimated oyster density per square meter also jumped significantly, at 432.07 live oysters/m² in Round 5, especially in East and North Bays. Off Little Oyster Bar Ridge had the highest estimated live oyster density in Round 5 (n=1181.07 live oysters/m²), representing the most dramatic increase in live oyster density from Round 4 (n=67.47 live oysters/m²). However, despite the growth, none of the areas have yet reached harvestable levels, with all but 2 sites being considered depleted (<100 bags/acre).
Our spatial extent estimations revealed that 58.22% of the reef areas (nearly 43 acres of 74 originally restored) still provide suitable hard substrate for oyster growth.
In Pensacola Bay, 24,144 live and 3,555 dead oysters have been sampled. While the number of live oysters sampled from Round 1 to Round 5 were not statistically significant when analyzed on a per sample basis, the latest round of sampling showed a significant increase in live oyster numbers compared to the previous round.
In Round 5:
Round 5 of sampling did show a significant increase in estimated live oyster density, at 81.73 live oysters/m², over Round 4's estimated 2.81 live oysters/m².
Consistent with all other rounds of sampling, Round 5 of sampling has shown that all sites in Pensacola Bay are considered depleted, with the most productive site only having an estimated 4.80 bags per acre of harvestable oysters.
Reef spatial extent data showed that 73.45% of the restored area (51.62 of the original 70.29 acres of restored reef) still contains suitable hard reef substrate, suggesting that the physical structure for future reef growth is still in place.